Ernst Weber, (born Sept. 6, 1901, Vienna, Austria—died Feb. 15, 1996, Columbus, N.C., U.S.), Austrian-born American engineer who was a pioneer in the development of microwave communications equipment and who oversaw the growth of the Polytechnic Institute in New York City.

Weber was educated in Austria and worked in Vienna and Berlin as a research engineer (1924–30) before visiting the United States, where he decided to remain. In 1930 he became a visiting professor at the Polytechnic Institute of Brooklyn (now Polytechnic University) in New York City, where he rose through various academic posts to become head of research and graduate study in electrical engineering (1942–45). He was afterward director of the Microwave Research Institute (1945–57) and its vice president for research (1957–63). He served as president of the Polytechnic Institute from 1958 to 1969 and president emeritus from 1969. He helped transform the Polytechnic Institute into one of the nation’s leading science and engineering centres.

Invited to join the government-sponsored Office of Scientific Research and Development at the beginning of World War II, Weber chose to study the little-explored but highly important field of microwave technology. With his associates, he developed a device for precise control of microwaves that proved useful in field tests of radar and built microwave measuring equipment.